Referring to FIG. 1, a conventional hinge disclosed in Taiwanese Utility Model Patent No. M412227 includes a connecting member 11, a pivoting member 12, a rotating shaft 13, a bolt 14, an abutment member 15, a resilient member 16, a seat member 17 and a throttle valve 19. The connecting member 11 is connected to a wall (not shown). The rotating shaft 13 extends rotatably through the connecting member 11. A central portion of the rotating shaft 13 is disposed in a first chamber 111 formed in the connecting member 11. The pivoting member 12 is connected to a door panel (not shown), and is connected co-rotatably to the rotating shaft 13 by the bolt 14. The seat member 17 is mounted in the connecting member 11. The abutment member 15 is disposed movably in the connecting member 11, extends movably into the seat member 17, and cooperates with the seat member 17 to define a second chamber 171 therebetween. The resilient member 16 is mounted in the seat member 17 to bias resiliently the abutment member 15 toward the central portion of the rotating shaft 13. The first and second chambers 111, 171 are filled with damping oil. The connecting member 11 is further formed with an oil passage 18 that communicates fluidly with the first and second chambers 111, 171. The throttle valve 19 is disposed in the connecting member 11 for adjusting the flow rate of the damping oil flowing through the oil passage 18.
When the pivoting member 12 is driven by an external force to rotate relative to the connecting member 11, the abutment member 15 is pushed by the central portion of the rotating shaft 13 to move away from the rotating shaft 13 against the resilient force of the resilient member 16. At this time, the damping oil in the second chamber 171 generates a retarding force to retard the movement of the abutment member 15, and is forced to enter the first chamber 111 through the oil passage 18. When the external force is removed, the abutment member 15 is biased by the resilient member 16 to move toward the rotating shaft 13, so as to drive the pivoting member 12 to rotate back to its original position. At this time, the damping oil in the first chamber 111 generates a retarding force to retard the movement of the abutment member, and is forced to enter the second chamber 171 through the oil passage 18.
The conventional hinge has the following drawbacks.
1. The door panel and the pivoting member 12 are usually made of stiff material. When opening or closing the door, the door panel may collide with the pivoting member 12 and may therefore be fractured.
2. The pivoting member 12 is connected to the rotating shaft 13 by the bolt 14, and may be loosed from the rotating shaft 13 easily.
3. A gap may be formed between the abutment member and the seat member 17 to affect the retarding force controlled by the throttle valve 19.
4. It is difficult to adjust the throttle valve 19 when the conventional hinge is placed inadequately, since the throttle valve 19 can only be adjusted at one side of the conventional hinge.